Rain Sensor Wiring

[BEM904]

I have no terminals on the timer box itself. Prior owner had rain senor located near valve box but wiring is disconnected. Two wires coming from rain senor. I realize one must attach to the common wire. Where does the other one go?

 

[Smooky]

Here is some info for a Rain Bird rain sensor:
http://www.rainbird.com/homeowner/support/timers/RSD.htm

 

[Sponsor]

 

[BEM904]

Thanks, but I am still confused by this.

So in the example of the RainBird model in the link you sent, I would wire the "red" wire to the COM wire coming from the timer and the "black" wire to the COM connection with the rest of the solenoids? Effectively, placing the senor in the circuit of the COM wire?

 

[WorthFlorida]

A rain sensor is nothing more than a switch to open the circuit when the leather washers inside the sensor expands and pushes on a pin to open the contacts. Therefore, the previous own installed one in series with the valve which works just the same. One wire to the valve and the other to the 24v wire to the valve. You do not have to open the common wire. Read the instruction on the package of the new rain sensor. Some can be options to be normally closed or normally opened contacts. You want normally closed, even if you had one on your timer.

No matter who makes the rain sensor, they all work the same and from my experience they do fail quite often (mex or china made), that is every few years in our Florida weather but I did have one that has lasted more than ten years and still working.